This invention relates to apparatus for loading disks from one container to another and, in particular, to a transfer mechanism which sequentially loads a pallet by walking disks along a cantilever.
In the manufacture of what is known as a hard disk for the magnetic storage of digital information, a variety of thin layers are deposited upon a flat, annular, metal member. The quality of these layers determines, in part, the amount of data which can be stored on a disk of a given size. It is thus desirable to handle the disks as little as possible so as not to damage the layers. Yet, in order to plate, or otherwise treat, the disks, it is necessary to handle them in order to move them from one processing station to another.
For several operations, the disks can be transported in a vertical pallet having a plurality of holes slightly larger than the outside diameter of a disk. The pallets provide a planar and bulky form of transport and are not always needed. Cassettes, or grooved boxes, provide a much more compact way to carry the disks, but are not amenable for use in processing the disks. Thus, it becomes necessary to perform some sort of transfer between these two types of holders.
There is a dilemma which arises when considering such a transfer, viz. the disks must be handled as little as possible yet the transfer cannot take a great deal of time. For example, the disks could be taken singly from a cassette and placed directly on the vertical pallet. This is too slow for commercial production of disks. Simply operating the transfer mechanisms more quickly is of no avail since the mass of the disks, while small, is not insignificant. Large accelerations require proportionately large equipment to maintain positional accuracies. Further, such accelerations cause large amplitude vibrations. More importantly, the disks are more likely to rub against the handling apparatus, producing particles which can contaminate the disks.
In view of the foregoing, it is therefore an object of the present invention to provide apparatus for transferring disks directly from a cassette to and from a vertical pallet.
Another object of the present invention is to provide apparatus for effecting such transfer with minimal handling of the disks.